DB2 SQL CONCAT AND COUNT

Question

I was trying to combine the result as below:

Current Result:

BOOKING_NUM | TYPE 1 | TYPE 2
Ref1        | 3      | (null)
Ref1        | (null) | 6

Expected Result:

BOOKING_NUM | TYPE 1 | TYPE 2
Ref1        | 3      | 6

I amusing the following query:

SELECT
    BEC.BOOKING_NUM
    ,CASE WHEN BEC.TYPE = '1' THEN COUNT(BEC.TYPE) END "Type 1"
    ,CASE WHEN BEC.TYPE = '2' THEN COUNT(BEC.TYPE) END "Type 2"
FROM    DB.EXCOM BEC
WHERE
    BEC.BOOKING_NUM = 'Ref1'
GROUP BY
    BEC.TYPE,
    BEC.BOOKING_NUM
ORDER BY
    BEC.BOOKING_NUM

I would love to seek for any suggestion. Thank you very much.

Tony

Answer 1

You need to apply your condition within max()

SELECT
     BEC.BOOKING_NUM
    ,max(CASE WHEN BEC.TYPE = '1' THEN BEC.TYPE END) "Type 1"
    ,max(CASE WHEN BEC.TYPE = '2' THEN BEC.TYPE END) "Type 2"
FROM    DB.EXCOM BEC
WHERE
    BEC.BOOKING_NUM = 'Ref1'
GROUP BY
    BEC.BOOKING_NUM
ORDER BY
    BEC.BOOKING_NUM